Promoting Engagement in the Drug Resistant TB-HIV Care Continuum in South Africa PRAXIS Study (PRospective Study of Adherence in M/XDR-TB Implementation Science) Aim 2

Tuberculosis (TB) remains the leading cause of morbidity and mortality worldwide among people living with HIV (1). Globally, the incidence of multidrug-resistant tuberculosis (MDR-TB) and extensively drug resistant tuberculosis (XDR-TB), the most drug-resistant forms of TB, has approximately doubled over the past fifteen years (1-3). Nowhere has this increased incidence generated more concern than in South Africa where interactions between TB and generalized HIV epidemics are causing 'explosive' TB incidence (4-6) and case-fatality are threatening to undermine the progress reached with antiretroviral therapy (ART) (7, 8).

Medication adherence, a key predictor of outcomes in M/XDR-TB and HIV treatment, is understudied in high burden TB-HIV settings (9-11). Patient losses during transitions in the care continuum are frequent (12), increase mortality and limit control of the linked epidemics. Demands of M/XDR-TB HIV treatment are severe including extraordinary pill burden, severe adverse effects, lengthy treatment, isolation and stigma with few parallels in modern medicine (13-15).